Olfactory Neuroblastoma-A Challenging Fine Line between Metastasis and Hematology

Abstract

Developing in a limited space, rare tumors located at the nose and paranasal sinuses are sometimes difficult to diagnose due to their modest clinical presentation, which is uncorrelated with anatomopathological diversity. This limits the preoperative diagnosis without added immune histochemical study; for that reason, we present our experience with these tumors with the intention of raising awareness. The patient included in our study was investigated by our department through clinical and endoscopic examination, imaging investigations, and an anatomic-pathological study. The selected patient gave consent for participation and inclusion in this research study in compliance with the 1964 Declaration of Helsinki.

Keywords: endoscopic surgery; management strategy; myeloma; olfactory neuroblastoma; rare sinonasal tumors.

Figure 1

Preoperative CT scan showing a nonspecific opacification of the right nasal fossa (inferior meatus) with partial erosion of the inferior turbinate. There was no evidence of invasion into the skull base, cribriform plate, or olfactory cleft. The CT scan demonstrated density and mucosal thickening of the maxillary sinus.

Figure 2

Olfactory neuroblastoma (HE stain, 40×) showing a solid and trabecular growth pattern composed of round, small cells that are relatively uniform with scanty cytoplasm and scattered chromatin pattern.

Figure 3

Immunohistochemical stain (PGP 9.5, ob 40×) showing intense cytoplasmic positive reaction of PGP 9.5 in all tumor cells.

Figure 4

PET-CT showed an activated metabolism (arrow) of a mass in the right iliac wing of 10/7.5 cm that invaded the neighboring endo- and exopelvic structures. The mass showed an inhomogeneous uptake of FDG. Other similarly moderate FDG-capturing osteolytic lesions could be distinguished in the right posterior fourth costal arch (invasive and dimensional progression compared to the CT scan performed 1 week before), the right fourth anterior costal arch, the left sixth lateral costal arch, the sternal manubrium, the medial angle of the scapula on the left, the C7 (with a major risk of subsidence), the T7 and T9 vertebral bodies, the right lateral clavicular extremity, the right humeral head, the apex, the right temporal bone, right parietal bone, and the left sciatic tuberosity.

Figure 5

The whole-body PET-CT showed (arrow) the activated metabolism of a 10 to 7.5 cm mass in the right iliac wing that invaded the neighboring endo- and exopelvic structures. The mass showed an inhomogeneous uptake of FDG. Other similarly moderate FDG-capturing osteolytic lesions could be distinguished in T7 and T9 vertebral bodies, the right lateral clavicular extremity, and the right humeral head.